Role of Cooling Techniques and Fuels in Enhancing Power and Efficiency of Gas Turbine Plants

2012 ◽  
Author(s):  
Mehaboob Basha ◽  
S. M. Shaahid ◽  
Luai Al-Hadhrami
Keyword(s):  
Gas Turbine

Modelling the Air-Cooled Gas Turbine: Part 1 — General Thermodynamics

2001 ◽  
Author(s):  
J. B. Young ◽  
R. C. Wilcock
Keyword(s):  
Gas Turbine ◽  
Performance Prediction ◽  
Real Gas ◽  
Thermal Mixing ◽  
Ideal Gases ◽  
Formal Framework ◽  
Considerable Simplification ◽  
Cycle Efficiency ◽  
General Thermodynamics

This paper is Part I of a study concerned with developing a formal framework for modelling air-cooled gas turbine cycles and deals with basic thermodynamic issues. Such cycles involve gas mixtures with varying composition which must be modelled realistically. A possible approach is to define just two components, air and gas, the latter being the products of stoichiometric combustion of the fuel with air. If these components can be represented as ideal gases, the entropy increase due to compositional mixing, although a true exergy loss, can be ignored for the purpose of performance prediction. This provides considerable simplification. Consideration of three idealised simple cycles shows that the introduction of cooling with an associated thermal mixing loss does not necessarily result in a loss of cycle efficiency. This is no longer true when real gas properties and turbomachinery losses are included. The analysis clarifies the role of the cooling losses and shows the importance of assessing performance in the context of the complete cycle. There is a strong case for representing the cooling losses in terms of irreversible entropy production as this provides a formalised framework, clarifies the modelling difficulties and aids physical interpretation. Results are presented which show the effects on performance of varying cooling flowrates and cooling losses. A comparison between simple and reheat cycles highlights the rôle of the thermal mixing loss. Detailed modelling of the heat transfer and cooling losses is discussed in Part II of this paper.

scholarly journals The Role of the Recuperator in High Performance Gas Turbine Applications

1978 ◽  
Author(s):  
C. F. McDonald
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Gas Turbine ◽  
Gas Turbines ◽  
High Performance ◽  
Waste Heat ◽  
Closed Cycle ◽  
Exhaust Waste Heat ◽  
Prime Movers

With soaring fuel costs and diminishing clean fuel availability, the efficiency of the industrial gas turbine must be improved by utilizing the exhaust waste heat by either incorporating a recuperator or by co-generation, or both. In the future, gas turbines for power generation should be capable of operation on fuels hitherto not exploited in this prime-mover, i.e., coal and nuclear fuel. The recuperative gas turbine can be used for open-cycle, indirect cycle, and closed-cycle applications, the latter now receiving renewed attention because of its adaptability to both fossil (coal) and nuclear (high temperature gas-cooled reactor) heat sources. All of these prime-movers require a viable high temperature heat exchanger for high plant efficiency. In this paper, emphasis is placed on the increasingly important role of the recuperator and the complete spectrum of recuperative gas turbine applications is surveyed, from lightweight propulsion engines, through vehicular and industrial prime-movers, to the large utility size nuclear closed-cycle gas turbine. For each application, the appropriate design criteria, types of recuperator construction (plate-fin or tubular etc.), and heat exchanger material (metal or ceramic) are briefly discussed.

Epicyclic Gearing for Gas Turbine Main Propulsion

1976 ◽  
Author(s):  
D. E. Yates
Keyword(s):  
Gas Turbine ◽  
Significant Role ◽  
High Power ◽  
Bulk Carrier ◽  
Merchant Marine ◽  
Future Role ◽  
Definite Advantage ◽  
The Future ◽  
Basic Concepts

The success of epicyclic gears in marine main propulsion has been well established. Their small size and weight has led to their introduction in many types of vessel. Epicyclic gears were used in many of the very early naval gas turbine powered vessels and, indeed since then, nearly 250 gears have been supplied for use with a marinized version of the “Proteus” gas turbine. The construction of this and other gas turbine propulsion gears is discussed in some detail to illustrate the basic concepts and design of the gearing. Because of the difficulties in providing astern power in a gas turbine powered ship without the use of a C.P. propeller, there has been interest in the use of a high power reversing gear. Here epicyclic gearing shows a definite advantage over the equivalent alternatives and indeed was used in the naval vessels referred to earlier. Some of the parameters relating to large reversing epicyclic gears are described and the future role of reversing gears is discussed. The description of recently delivered merchant marine triple reduction epicyclic gears is given. The gears transmit 8200 kw from an industrial type of gas turbine and are each installed in a 45,000 tons bulk carrier. Epicyclic gears have played a significant role in the development of gas turbine ship’s propulsion and their future role is discussed in relation to present and projected requirements.

A Diagnostic Expert System for Oil Systems of Aeroengines

1993 ◽  
Author(s):  
Hong Cao ◽  
Mei Ma
Keyword(s):  
Artificial Intelligence ◽  
Expert System ◽  
Gas Turbine ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Complex Relation

DIAG, a diagnostic expert system for oil systems of aeroengines, is presented in this paper. Using artificial intelligence, DIAG, which simulates the role of human experts in solving problems, can solve the complicated problems in diagnosing the faults and failures of oil systems of gas turbine engines. The paper concentrates on the design of DIAG as well as the process of handling the complex relation and uncertainty of problems. It also includes graphic subsystem and data subsystem. It is affirmed by the expected goal of diagnosing the faults and failures of oil system and engine of CFM56 engine on Boeing 737–300 airplane.

CFD Analysis of Industrial Gas Turbine Exhaust Diffusers

2002 ◽  
Author(s):  
V. Vassiliev ◽  
S. Irmisch ◽  
S. Florjancic
Keyword(s):  
Gas Turbine ◽  
Measurement Data ◽  
Turbulence Models ◽  
Cfd Analysis ◽  
Cfd Modelling ◽  
Gas Turbine Exhaust ◽  
Key Aspects ◽  
Industrial Gas Turbine ◽  
Turbine Exhaust

The key aspects for the reliable CFD modelling of exhaust diffusers are addressed in this paper. In order to identify adequate turbulence models a number of 2D diffuser configurations have been simulated using different turbulence models and results have been compared with measurements. An automated procedure for a time- and resource-efficient and accurate prediction of complex diffuser configuration is presented. The adequate definitions of boundary conditions for the diffuser simulation using this procedure are discussed. In the second part of this paper, the CFD procedure is being applied to investigate the role of secondary flow on axial diffusers. Prediction results are discussed and compared with available measurement data.

scholarly journals Coal Mineral Matter Transformation During Combustion and its Implications for Gas Turbine Blade Erosion

1990 ◽  
Author(s):  
S. Rajan ◽  
J. K. Raghavan
Keyword(s):  
Gas Turbine ◽  
Turbine Blade ◽  
Coal Dust ◽  
Turbine Blades ◽  
Mineral Matter ◽  
One Dimensional ◽  
Gas Turbine Blades ◽  
Edx Analysis ◽  
Ft Ir

The transformation of mineral matter during combustion and the characteristics of the ash formed are important from the standpoint of coal fired gas turbine operation. Using a novel FT-IR technique and EDX analysis, these mineral matter transformations are investigated when the coal is burnt in a one-dimensional pulverized coal-dust-air flame. The role of clays, pyrite, quartz, potassium and other compounds in the ash are discussed with particular reference to deposit buildup and erosion of gas turbine blades.

scholarly journals Thermodynamic analysis of the double Brayton cycle with the use of oxy combustion and capture of CO2

2013 ◽  
Vol 34 (2) ◽  
pp. 23-38 ◽  
Author(s):  
Paweł Ziółkowski ◽  
Witold Zakrzewski ◽  
Oktawia Kaczmarczyk ◽  
Janusz Badur
Keyword(s):  
Gas Turbine ◽  
Thermodynamic Analysis ◽  
Compression Ratio ◽  
Negative Pressure ◽  
Condensation Process ◽  
Brayton Cycle

Abstract In this paper, thermodynamic analysis of a proposed innovative double Brayton cycle with the use of oxy combustion and capture of CO2, is presented. For that purpose, the computation flow mechanics (CFM) approach has been developed. The double Brayton cycle (DBC) consists of primary Brayton and secondary inverse Brayton cycle. Inversion means that the role of the compressor and the gas turbine is changed and firstly we have expansion before compression. Additionally, the workingfluid in the DBC with the use of oxy combustion and CO2 capture contains a great amount of H2O and CO2, and the condensation process of steam (H2O) overlaps in negative pressure conditions. The analysis has been done for variants values of the compression ratio, which determines the lowest pressure in the double Brayton cycle.

scholarly journals On the effects of hydrocarbon and sulphur-containing compounds on the CCN activation of combustion particles

2005 ◽  
Vol 5 (3) ◽  
pp. 2599-2642 ◽  
Author(s):  
A. Petzold ◽  
M. Gysel ◽  
X. Vancassel ◽  
R. Hitzenberger ◽  
H. Puxbaum ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Gas Turbine ◽  
Sulphuric Acid ◽  
Organic Compounds ◽  
Operating Conditions ◽  
Water Soluble ◽  
Data Set ◽  
Combustion Particles ◽  
Volatile Organic

Abstract. The European PartEmis project (''Measurement and prediction of emissions of aerosols and gaseous precursors from gas turbine engines'') was focussed on the characterisation and quantification of exhaust emissions from a gas turbine engine. A comprehensive suite of aerosol, gas and chemi-ion measurements were conducted under different combustor operating conditions and fuel sulphur concentrations. Combustion aerosol characterisation included on-line measurements of mass and number concentration, size distribution, mixing state, thermal stability of internally mixed particles, hygroscopicity, cloud condensation nuclei (CCN) activation potential, and off-line analysis of chemical composition. Modelling of CCN activation of combustion particles was conducted using microphysical and chemical properties obtained from the measurements as input data. Based on this unique data set, the role of sulphuric acid coatings on the combustion particles, formed in the cooling exhaust plume through either direct condensation of gaseous sulphuric acid or coagulation with volatile condensation particles nucleating from gaseous sulphuric acid, and the role of the organic fraction for the CCN activation of combustion particles was investigated. It was found that particles containing a large fraction of non-volatile organic compounds grow significantly less at high relative humidity than particles with a lower content of non-volatile OC. Also the effect of the non-volatile OC fraction on the potential CCN activation is significant. While a coating of water-soluble sulphuric acid increases the potential CCN activation, or lowers the activation diameter, respectively, the non-volatile organic compounds, mainly found at lower combustion temperatures, can partially compensate this sulphuric acid-related enhancement of CCN activation of carbonaceous combustion aerosol particles.

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